William gaeeoll



(No Model.)

W. CARROLL.

FIRE ALARM SIGNAL CIRCUIT. No. 382,253.- Patented May 1.. 1.888.

UNITED STATES j PATENT OFFICE.

WILLIAM CARROLL, OF CHICAGO, ILLINOIS, ASSIGNOR TO JOHN P. BARRETT, OFSAME PLACE.

FlRE-ALARM-SIGNAL CIRCUIT.

SPECIFICATION forming part of Letters Patent No. 382,253, dated May 1,1888.

' Application filed February 6, 1888. Serial No. 263,097, (No model.)

To (LZZ whom it may concern.-

Be it known that I, WILLIAM CARROLL, a citizen of the United States,residing at Ohicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Fire-Alarm-SignalCircuits, (Case 1,) of which the following is a full, clear, concise,and exact description, reference being had to the accompanying drawing,forming a part of this specification.

My invention relates to electric fire-alarmsignal systems, in whichsignals are trans- -1nitted from the central fire-alarm oilice tovarious engiuehouses distributed throughout the city. In such systemstwo independent circuits are usually employed, which extend respectivelythrough each of the enginehouses. As is well understood, when a box of agiven number is turned in to the central ofiice, this signal or numberis first repeated over one of the lines extending through theengine-houses and then on the other of said lines. These signals beingreceived at the various engine-houses indicate the number of the boxturned in, and thus the location of the fire where the services of thedepartment are required.

In order that the whole force in the city may not be called out at onceupon every alarm of fire, the companies at the different engine-housesare assigned to different districts and instructed to respond to certaincalls, respectively. In the day-time, in order that no time may be lost,all of the companies upon the first call get in position, ready to startas soon as the complete signal is received.

The companies not within the district of the box from which the call wassent do not start out, however, but unhitch their horses. Such hitchingup and unhitching in the daytime is not objectionable, and isofadvantage, in that the men are thereby drilled and the horses kept intraining. In the night, however, such work should be avoided. In thesystem of John P. Barrett, described in Letters Patent No. 376,132, thecircuits are so arranged that the large gong'and the door-opener orchaindropper at any engine-house may be cut out of the circuit, exceptin case of calls which are from the district of that particularenginehouse. In the Barrett system, however, it is necessary to dependupon the watchman to turn a switch at the proper time to bring the largegong and door-opener into circuit.

The object of my invention is to prevent a disturbingthe men orunhitching the horses,

while the signal over the second line will operate the door-opener andsound the alarm, unless the attendant shall between the time of thefirst signal over the first line and that of signal over the second wiremove a switch to open the local circuit of the relay orsmall bell of thesecond line, which local circuit includes the gong and door-opener. Theline over which the first signal is sent is sometimes called the jokerline, while the other or second line is usually called the gong line.

In the joker-line I place a relay connected with a local circuitcontaining a register, the register serving also as a relay in a localcircuit containingthelargegong and door-opener, or one oftheseinstruments. A manual switch is also provided in this latter localcircuit. The gong-line is connected through a small gong or bell,whichserves as a relay in a local circuit, including also a manual switch andthe large gong and door-opener, or one of these instruments. If thislocal circuit is closed by the switch, the large gong will be soundedwhen the current is sent through the small bell, which is connected upas a relay to open and close the generalalarm local circuit at eachstroke of the small bell.

My invention is illustrated in the accompanying drawing, in which I haveshown a diagram of the circuits and apparatus at an en gine-houseillustrative of my invention.

The joker line or circuit a is connected through the coil of theelectro-magnet of the relay 6, which is placed with contacts in thelocal register circuit c. The register at serves also as a relay withcontacts included in the general-alarm local circuit e. This circuitincludes a switch, f, and the battery the large gong h, and anelectro-magnet, i, which serves ICO to operate the door-opener orhorse-unhitcher in a manner not necessary to describe herein.

The gong-line includes a small bell, Z, which is connected. as a relayin the general-alarm local circuit m. Local circuit at contains aswitch, a, and also the battery 9, a large gong, h, and electro-magneti. It should be observed that the said battery, gong, and door-openerare common to the local circuit 6 and local circuit m. The switchesfanda are mechanically independent, so that either may be operated withoutdisturbing the other.

In the day-time the switchesf and a may remain in the positionsindicated by full lines. The signal, being sent in first over linea,will be received upon the register and sound at the same time thealarm for the company to get' ready; the horses, being at the same timeunhitched, trot to their places. The signal is again repeated overcircuit 7c, and of course repeats the signal upon the large gong.

By opening switchfthe signal sent over line a is prevented from soundingthe general alarm. The watchman,noting this first signal at theregister, will at once open switch a before the signal begins to come inover gongline k, if the number is that of a. box outside hisengine-house district. The switch a being thus opened, the signal willbe received upon the small bell, and no general alarm, or alarm to getready to start,will be sounded. .Thus at night,or at other times,thegeneral alarm may not be given. If, however, the watchman should neglector fail to open switch a, the door-opening electro-mag-net will beoperated and the large gong sounded on the comingin of the signal overthe gonglinc 70. Thus there can be no failure in the sounding of the general alarm, even though the watchman should fall asleep at his post. Thepush-key 0 is shown connected with the general-alarm circuit containingthe battery g, gong h,and dooropener t, in such manner that the watchmanmay,after noting the first signal upon the register, operate thedoor-opener and sound the gong before the signal is sent in overthegongline.

My invention admits of various modifications, which will readily suggestthemselves to those skilled in the art, and I therefore do not limit myinvention tothe precise construction shown.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. A door-opening electromagnetic device, an electricgong, and a battery in a wire common to two different local circuits,each of said local circuits containing a different sw it ch,and eachbeing mechanically independent of the other and connected through thecircuit-closing points of a different relay, one of said relays beingconnected to be energized in unison with the signal sent over thejoker-line of the system and'the other of said relays being connected tobe energized in unison with the sig nal sent over the gong-line of thesystem, in combination with said joker-line and gongline, whereby thebattery in said common wire may be closed to operate said door-openingelectromagnetic device and electric gong by signals sent over both thejoker-line and the gong-line, the gong-line alone, or neither of saidlines, according to the positions of the switches.

2. The combination, with two independent signal-circuits over whichsignals are sent in succession, of a relay or repeater in each of saidcircuits connected with local circuits,each local circuit including aswitch, the switch in one circuit being independent of the switch in theother circuit, and a portion of said local circuits being common, thecommon portion including a local battery and a signal device, wherebywhen a signal is sent first over one signal-circuit the local circuitcontaining the relay of the other signal-circuit may be opened beforethe signal is sent over said second circuit.

3. The combination, with the twosignal-circuits of a fire-alarm system,one of said signalcircuits, thejoker-line,co'ntaining a relay in aregister local circuit, of the register in a local circuit containing aswitch and general-alarmsignal device, and the other of saidsignal-circuits, the gong-line, containing a bell connected up as arelay in a local circuit containing a other switch, said switches beingmechanir ally independent of said general-alarm-signal device, wherebythe first signal sent over the joker-line may be received uponthegegister without operating the general-alarm device, while the signalsubsequently sent over the gong-line may be allowed to operate thegeneral alarm or not,at the will of the watchman, accordingly as heleaves the switch in the local circuit of the small bell of the gong-line closed, or opens the same after noting the first signal receivedupon the register.

In witness whereof I hereunto subscribe my name this 3d day of February,A. D. 1888.

NVILLIAM CARROLL. Witnesses:

CHAS. G. HAWLEY, GEORGE P. BARTON.

